Solitract
by ftlow
Summary: "What if you do something it hasn't dealt with before, like reverse the polarity or something?" "Yasmin Khan! You speak my language." Except, Yaz thinks, she doesn't, does she? Not at all. She has no idea what it means to be The Doctor. If she's honest with herself, she has no idea who The Doctor is or where she appeared from. And maybe... maybe she'd like to understand, or try to.


The Doctor turned the key and strode inside, sighing heavily.

Yaz followed slowly, glancing back at Graham. Ryan followed her gaze and stopped, turning back. She squeezed his shoulder and stepped inside the TARDIS, giving them a moment to themselves.

The Doctor was stood with her hands on the console, arms braced, head dropped, eyes squeezed closed.

Yaz frowned. That was… she wasn't sure what word she was looking for, exactly. She felt the same apprehension as when the Doctor had announced earlier that she was scared, or way back at the start of their adventures, on Desolation, when she thought she'd failed to find the TARDIS and get them back home. The helplessness that had filled her eyes when Willa's granny had died. It was unnerving, to say the least, to see such a self-assured, confident woman so…vulnerable.

Yaz thought back through the day's events. It had to be Grace.

"You think Graham blames himself…why?" She asked.

The Doctor glanced up and shook herself. "Because he's still here," she replied grimly. "Doing penance. Saving people. Seeing everything she should have. Grace was built for this sort of life, but Graham isn't, he's doing it for her." She dropped her gaze. "And if he blamed me, he wouldn't be here, doing that. He'd be at home, where he belongs, grieving."

Yaz frowned. "_You_ blame yourself," she recognised aloud. The Doctor startled, but didn't meet her gaze - all the confirmation Yaz needed. She stepped closer, cautiously. "It wasn't your fault," she murmured. "That cheating Tim Shaw and his illegal coil killed Grace. And she wasn't supposed to be in the compound anyway, you told her to stay out. It was in her nature to act."

The Doctor flinched as Yaz reached out to put a hand on her shoulder, stepping away. "Trouble follows me, or I follow it, I'm never quite sure which one. But either way, I… corrupt everything. Everyone."

Yaz shook her head. "You show us wonders, Doctor. You show us the universe, and you help to save it. You think everyone is important, every tiny person, even though the universe is so huge, and that's…that's incredibly humbling."

The Doctor shook her head wordlessly and turned away. Yaz caught her hand, just as the Doctor had done to her earlier, and tugged, spinning her back towards her and unbalancing her enough to throw her arms around her.

"None of us blame you for Grace. We're all still here, because we want to be," Yaz murmured, and the Doctor stood stiff in her arms, her dual heartbeat pounding through her cool skin.

Yaz eventually let go, and sighed. "One day you'll believe me," she announced.

The Doctor smiled sadly at her. The door opened behind her, bringing in a smiling but quiet Ryan and a pensive Graham, and Team TARDIS took up their usual positions while the Doctor began her usual dance around the console.

If it was a little flatter and less energetic than usual, only Yaz noticed.

* * *

Days later, they were in Sheffield. Graham and Ryan were having some much needed alone time, bonding and remembering Grace in the house they'd both been avoiding.

Yaz had fetched some things she needed from home and worked an early shift. Now her family were all out at work themselves, and she was at a loss for anything to do, so she headed back to the TARDIS.

The Doctor hadn't been herself since their last adventure. Yaz could see it in the slump of her shoulders and the absent wrinkles around her eyes and nose when she smiled.

Yaz knocked on the TARDIS's blue doors, and the right-hand one swung in with a small click. _That's new_, she thought. Normally only the Doctor had that privilege, and only if she'd lost her key.

Yaz slid quietly in and pulled the door softly closed behind her. The incredible hexagonal interior glowed with its usual orange from the crystals that looked oddly like the legs of a giant creature crouched above.

It was quiet. The TARDIS's machine noise was a gentle whir, a comforting and soft hum. Yaz's work boots clanged quietly on the metal floor.

"Donna?"

Yaz frowned as the Doctor appeared from behind the console, standing and turning; she'd obviously been sat on the floor with her back against the other side of the console.

"Oh, Yaz, of course. Sorry," she smiled as she brushed herself down needlessly, hovering near the console. Then, taking in the uniform - minus the high vis vest - and Yaz's rucksack, she stood taller, flashing a teasing grin. "Excuse me, PC Khan, I mean. Did I ever tell you about my friend Amy? Second time I met her she was dressed as a police officer, but turns out she was a kissogram, not police at all! I was so excited to have a real police person in my police box, but I guess I had to wait another few hundred years until you came along. But now here you are! A real actual police officer with a proper uniform and a car and everything! I've always wanted to try having the lights and sirens on, I drove the TARDIS down a dual carriageway once but it's not really got the same effect as -"

"Doctor."

The Doctor stopped, half-smiled, and took a breath. "I…guess you're staying then?"

Yaz smiled, half-pleased she'd correctly interpreted the babbling for nerves and half-pleased that for a moment at least, the Doctor was acting her usual bubbly self.

However, the question and the uncertainty behind it troubled her.

"Of course I am, Doctor. If that's okay with you. Why wouldn't I?"

The Doctor just shrugged, and Yaz decided not to push it. She changed the subject, coming closer and leaning her rucksack against one of the crystals, throwing herself down on the floor in the hope the Doctor might join her.

She did, hesitantly, and hugged her knees.

"Who's Donna?" Yaz asked curiously.

The Doctor sighed. She'd probably expected the question, Yaz thought, as soon as the name had slipped out.

"She…we used to travel together, once. Lifetimes ago."

Yaz frowned. "Why did you expect her?"

The Doctor shook her head. "I didn't, not really. I was just thinking about her when you came in. You… you reminded me of her. Last time. She… there was a bit of an accident and she ended up absorbing all my knowledge. Kind of, not really, but sort of. She had all the technical stuff figured out, and when you suggested reversing the polarity it all came back."

_Yasmin Khan, you speak my language._

Yaz smiled at the memory.

"That sounds like a good sort of accident. Imagine how much more useful we'd be if we all knew as much as you," she said lightly, nudging the woman beside her.

The Doctor glanced sharply at her and shook her head.

"The sheer quantity of it would kill you. I had to take away all Donna's memories of travelling with me, and the man I was then. She can't ever remember, or she'd die."

She tore her eyes away and fiddled with the hem of her coat. Her shoulders were rounded as she slouched against the console. She looked defeated.

Yaz opened her mouth, and then closed it again.

Eventually, she said quietly, "Did you see her? In the mirror world?"

The Doctor shook her head. "The Solitract didn't show me anyone. It didn't need to." She spared a glance at Yaz's apologetically-intrigued expression and sighed. "My race are telepathic, kind of, ish. The Solitract used telepathy to recreate physical representations of lost loved ones for Graham and Erik, non-telepathic beings. But we…we could have conversations, share experiences, and exist outside of time entirely, without exchanging a single physical word."

Yaz stared at her. "You…can read minds?" She asked.

"I…sort of. Not…not really. That's a human interpretation of what telepathy means, the human definition of the human word _telepath_… it's not quite that simple."

Yaz sighed. "I don't think I'll ever really get my head around what it means to be you. You're so human most of the time that I forget you're not."

The Doctor smiled thinly. "I know," she murmured. "And sometimes, caught up in the beauty or the terribleness of your Earth, so do I."

She tore her eyes away and picked again at the edge of her coat.

"So…you didn't see Donna, but your memories of her were…reopened?" Yaz asked hesitantly.

The Doctor looked up, surprised. "Yes, I suppose that's what it was like… the Solitract went through my experience of living. When I convinced it to send Erik back, I offered my life, because it's so much deeper and longer than any one human life. And the Solitract sifted through… everything. Family, friends, enemies. Desperation, grief, sadness, love. Regeneration. All the bad things and good things I've done, all the people I've saved and failed to save. Everything I've lost. Everyone I've been. Everyone I've loved." She blinked herself back to the present and shook her head. "Timeless. As if I've relived it all, been through it all again, moments ago."

"You…you were only gone for a few minutes," she said hesitantly, "right?"

The Doctor nodded. "Yes, and no. I offered myself to the Solitract. I thought it was permanent. In a way, it was. But the parallel universe was unstable. The Solitract took my emotions, and learned pity. Learned the beauty and the horror of living and sent me back. But I was there with the Solitract infinitely."

Yaz blinked in confusion and shook her head. "I don't understand. You offered to stay? You would have stayed, if the universe wasn't collapsing?"

"If that's what it took to keep both universes from disappearing, yes. Technically, I did stay. It's timeless… I'm still there, in some ways." She glanced at Yaz, and chose not to try and expand on that. "Yes, I would have stayed," she concluded. "I care about too many people on earth and in this universe to let it tear itself apart. You three were in the right time zone and on the right planet, you'd have found your way home."

Yaz squinted. "But…you'd have been alone."

The Doctor laughed hollowly. "Yes. Tell me, Yaz; what would you choose? An eternity of being alone, or eternally outliving and losing loved ones?"

Yaz swallowed. It hit her, suddenly, just what it meant to be immortal - if indeed the Doctor was that. To lose everyone, over and over, and have to get up and carry on.

"Doctor… how old are you?"

The Doctor laughed again, a strained, uneasy sound, not her usual cheerful outburst.

"That's an impossible question," she replied, mouth still quirked up at the corners. "Every planet has a different definition of a year. Every timeline I visit crosses over with another. I have memories from a whole year on Earth that never actually happened, in the end. I restored the Universe when every star in the sky except your sun went out. I spent four and a half billion years dying and recreating myself. I spent a single night on Darillium and that night was the same length as twenty-four Earth years. I lived on Trenzalore for nine centuries, to defeat it." She shook her head. "I wouldn't have a clue how old I am any more."

Yaz's head was spinning. "How… how can you possibly exist outside of time?" She wondered aloud, staring at the Doctor's downcast eyes. "I know you do, but… How can that be?"

"You forget, again. I'm not human. I don't feel things the way you do, I don't see things the way you do. Donna did, and she nearly died."

There was a long silence as Yaz considered what little she knew of this Donna, and everything the Doctor had said.

_Everyone I've loved._

"You loved her," Yaz realised aloud.

The Doctor looked up. "Who?"

"Donna."

She wrinkled her nose. "Not… the way you mean. Donna was fantastic, of course she was. I loved travelling with her. But nothing… romantic, or whatever. It's…not that simple."

Yaz considered the Doctor, head on one side. "But there have been others. Other people, and other not-human people. Right?"

The Doctor nodded. "So many," she sighed. "I've been married, before. Had a family once. And lots of people have travelled with me. Every one is so special."

The silence stretched, then, and Yaz wasn't sure how to break it. Eventually she blurted awkwardly, "Doctor, what are you? If - if you're not human, I mean…"

The Doctor sighed, and smiled, and shook her head. "I am a Time Lord," she replied. "In fact, I am the last of the Time Lords. And my home planet was Gallifrey."

"Time Lords?"

"Yes. We were exposed to the time vortex, and that affected our physiology eventually. We have… extra senses, I suppose you'd call them. I can see time, all of it at once. I can see possible outcomes of actions not taken, I can see fixed points in history and in the future, I can see whole timelines erasing and rebuilding as pasts and futures change."

Yaz blinked. "So… when you said to be careful in the Punjab because I was treading on my own history and my whole timeline could be erased…"

"I could see the universe without you in it, yes. And I didn't like it."

Yaz blinked again, and then shook her head. "Now I understand why Donna needed to forget," she said quietly. "That much information… that responsibility…"

The Doctor glanced at her and smiled thinly. "Yeah," she murmured.

After a few moments of silence, the Doctor pulled Yaz to her feet and hurried off to make tea. Yaz hit the pedal that produced custard creams and followed more slowly, turning the conversation over in her mind.

"Doctor," she started as she entered the vaguely kitchen-like room, clutching the biscuits to her, "what did you mean, you're the last of them?"

The Doctor stopped, frozen, her back to Yaz. Then she slowly put down everything she was holding and turned around, leaning on the counter behind her.

"My race was proud, powerful, and flawed, as all races become when they get used to power. There was a war, and we lost." The Doctor turned away. "My planet was destroyed. My people were destroyed."

Yaz stepped up beside her to finish making the tea, an apology on her tongue. She stammered it out, reflecting that perhaps, now, she understood the Doctor's fascination with humanity.

It gave her something - somewhere - to _almost_ belong.


End file.
